We tried Commons CLI on one project a few years ago, but at the time it seemed like a very odd, cumbersome API. Maybe that's changed, I don't know. For the few command line args I've had to parse, I just manually walk the array and hand-code it. For apps with a handful of args, this seems preferable to sucking in yet another "mini framework".

I haven't had an opportunity yet to use it, but I have been keeping my eye on Groovy's CLIBuilder, which seems dead simple. Here is an example of it being used, http://docs.codehaus.org/display/GROOVY/WrappingGroovyScript